Thin film transistor liquid crystal display (TFT-LCD) is a major flat panel display (FPD). The TFT-LCD is more and more popular in the field of high-performance display field because of its characteristics of small size, low power consumption, radiation free and low production cost.
A TFT-LCD includes a first substrate (e.g., an array substrate), a second substrate (e.g., a color film substrate) and a liquid crystal (LC) layer interposed between the first substrate and the second substrate. The first substrate is provided with a TFT array, and the second substrate is provided with a color filter and a black matrix. An upper polarizer is provided on the second substrate, and a lower polarizer is provided on the first substrate. Light transmission axes of the upper polarizer and the lower polarizer are orthogonal. According to different directions of the electric field driving the LC, the TFT-LCD may be classified into a vertical electric field type and a horizontal electric field type. In the vertical electric field type TFT-LCD, a pixel electrode may be formed on the first substrate and a common electrode may be formed on the second electrode. In the horizontal electric field type TFT-LCD, both the pixel electrode and the common electrode may be formed on the array substrate.
It should be noted that, information disclosed in the above background portion is provided only for better understanding of the background of the present disclosure, and thus it may contain information that does not form the prior art known by those ordinary skilled in the art.